蚀刻腔条件对刻蚀工艺的影响研究

Study on the Influence of Chamber Wall Condition on Etch Process

在ULSI制造中蚀刻腔条件的变化是导致刻蚀工艺重复性差的一个重要原因。在刻蚀过程中,一层聚合物会淀积在蚀刻腔壁上。通过XPS分析得知,聚合物的主要成分为(CF2)n。实验过程发现不同的聚合物量会影响等离子体中CF2基团的浓度。聚合物越多,CF2浓度越高;反之,聚合物越少,CF2浓度就越低。在这种情况下,蚀刻腔上的聚合物被认为是等离子中CF2基团的一个源。CF2浓度的变化又导致最终刻蚀特性(CD,蚀刻率)的变化和工艺漂移。

The variation of chamber wall condition is one of the key factors of process irreproducibility in manufacturing of ULSI. During etching, a polymer film would be deposited on chamber wall, and the main composition is （CF2）n examined by XPS. Experiment result shows that different polymer coverage amount on chamber wall will result in different CFa concentrations in higher CF2 concentration and chamber wall is considered as fewer polymers lead to a source of CF2 in plasma plasma More polymers on chamber wall produces lower CF2 concentration. In this case, polymer on ~ The variation of CF2 concentration in plasma results in the change of etching property and process shift.